CARDIORESPIRATORY TRANSFER IN OBSTRUCTIVE SLEEP APNEA

描述（改编自申请人的摘要）： 拟议项目有三个方面。 一是量化动态 呼吸对阻塞性心脏病患者心率控制的影响 睡眠呼吸暂停综合征（OSAS）在清醒和睡眠。 第二主 目的是评估持续气道正压通气的长期效果 压力（CPAP）治疗对OSAS患者心肺功能转移的影响， 阐明可能导致这些变化的机制。 第三个目标是 开发一个功能定量模型， 呼吸和心率控制之间的动态耦合， 了解潜在的生理机制。 动态模型 将心率的波动与以下变化相关：（a）瞬时 肺容量，（B）呼吸驱动，和（c）动脉血压。 正常 无打鼾者、高血压无打鼾者和OSAS患者在6 将在4个系列的实验中研究CPAP治疗的3个月。 变化 阻塞性睡眠呼吸暂停综合征的心肺转流及CPAP治疗的疗效 在减少这些变化将通过比较评估模型 参数和跨受试者组的导出传递函数。 在 系列1a，心肺传递函数（CTF）将在 在自主和受控呼吸条件下的清醒。 在 系列lb，CTF将在清醒和睡眠中以及在 在睡眠中应用以下干预：高氧， 常氧CPAP和CPAP期间的周期性声诱导觉醒。 在 系列2和3a计算机控制的呼吸机将提供随机 呼吸辅助水平和随机发生的闭塞 不同的睡眠阶段。 这些扰动将增强模型参数 通过减少输入变量之间的相关性来改进估计过程。 在 系列3：声刺激唤醒睡眠时的自主神经反应 将比较CPAP治疗前和治疗后6个月的OSAS受试者。 本研究中验证的方法可能提供一种客观的方法， 预测OSAS患者发生潜在致命性心脏病的风险 心律不齐

DESCRIPTION (Adapted from the applicant's abstract): The major goals of the proposed project are threefold. The first is to quantify the dynamic effects of respiration on heart rate control in subjects with obstructive sleep apnea syndrome (OSAS) during wakefulness and sleep. The second major objective is to assess the long-term effects of continuous positive airway pressure (CPAP) therapy on cardiorespiratory transfer in OSAS and to elucidate the mechanisms that may underlie these changes. The third goal is to develop a functional quantitative model that can characterize the complex dynamic coupling between respiration and heart rate control and enhance our understanding of the underlying physiological mechanisms. The dynamic model will relate fluctuations in heart rate to changes in: (a) instantaneous lung volume, (b) respiratory drive, and (c) arterial blood pressure. Normal non-snorers, hypertensive non-snorers, and OSAS patients before and after 6 months of CPAP therapy will be studied in 4 series of experiments. Changes in cardiorespiratory transfer due to OSAS and the efficacy of CPAP therapy in reducing these changes will be assessed by comparing the estimated model parameters and derived transfer functions across the subject groups. In Series 1a, cardiorespiratory transfer functions (CTF) will be estimated in wakefulness under spontaneous and controlled breathing conditions. In Series lb, CTF will be estimated in wakefulness and sleep, as well as during the application of the following interventions in sleep: hyperoxia, normoxic CPAP, and periodic acoustically-induced arousals during CPAP. In Series 2 and 3 a computer-controlled ventilator will provide randomized levels of respiratory assistance and randomly-occurring occlusions during various sleep stages. These perturbations will enhance the model-parameter estimation process by reducing correlation among the input variables. In Series 3 the autonomic responses to acoustically-induced arousals from sleep in OSAS subjects before and after 6 months of CPAP therapy will be compared. The methods validated in this study may provide an objective means of predicting in OSAS patients the risk of developing potentially fatal cardiac arrhythmias.